1. Field of the Invention
This invention relates to a coordinate position information output device, and more particularly to a coordinate position information output device in which information at the coordinate position addressed with a contact pen, light pen, heat pen, magnetic pen or the like is applied to a display device to effect writing, erasing, etc.
2. Description of the Prior Art
In the field of graphic display, since a high value is set on man-machine communication, it is necessary that coordinate information to be addressed is properly generated by an operator's addressing. A known device for generating such coordinate information is an address tablet having a matrix-like electrode arrangement and called RAND TABLET, and it is employed in a display system of the type using a cathode ray tube.
However, such a conventional coordinate position information output device involves complicated peripheral circuits. Further, in this known device, information at a coordinate position is provided in a coded form suitable for application to a computer, so that, in order to address a matrix-like display device, it is necessary to decode the output information through a computer and then to designate a coordinate position to be addressed and drive a drive circuit. There has also been proposed such a method that, in a display panel having a matrix-like electrode such as a plasma display panel, a coordinate position is addressed directly with a voltage pen or light pen for writing and erasing. With this direct pen address system, however, an accurate operation cannot be expected and many problems still remain unsettled for putting this system to practical use and, in addition, it is impossible to apply an input from a desired position apart from the display panel.